I have several 3570 Model C12 devices are are working nicely with my 2 ADSM
v3.1 servers (on AIX 4.2 and 4.3)
For the most part I have compression OFF on my clients (NT, Novell).

In my dev class defintion I have FORMAT=DRIVE
In my device defintion I have DEVICETYPE=3570

Optimal compression may return a 3:1 ratio (depending on the client platform)

If I query a client's space(looking at space utilization on the client itself)
before backup it may say 500M. When the backup is complete and I query the
client occupancy it may say 500M. Is this a 1-to-1 ratio How can I tell if the
hardware is doing compression??